Recording apparatus



Feb. 17, 1948. D, E. SUNSTEgN 2,436,235

RECORDING APPARATUS Filed May 5, 1944 5 Sheets-Sheet l Feb. 17, 1948, l D E SUNSTEiN 2,436,235

RECORDING APPARATUS Filed May 5f 1944 5 Sheets-,Sheet 2 Feb. 17, 1948. Q E SUNSTEiN 2,436,235

'RECORDING APPARATUS I Filed May 5, 1944 5 Sheets-Sheet 5 Feb 17, N943 D. E. SUNSTEIN RECORDING APPARATUS Filed May 5, 1944 5 Sllef-:s-Shee FiledhMay 5, 1944 5 Sheets-Sheet 5 Patented Feb. 17, 1948 UNITED STATES PATENT FFIC 2,436,235 RECORDING ArPARArrUs David E. Sunstein,v Elkins Park, Pa.,r assignor to Philcov Corporation,Philadelphia, Pa., a corporation of Pennsylvania.

Application May 5, 1944, serial No. 534,384

semanas. (01.234-) This invention relates to a novel: apparatus for accurately recording the totalized revolutions of a rotating shaft ata given` instant, and more particularly the invention relates to an apparatus of this character which is adapted for use ina system for rapidly and. accurately calibrating` a variable frequency generator, by comparison with a standardv signal generator capable of generating abandof frequencies over which the variable frequency generator is` to bet-calibrated.

Recent developments in the manufacture. of highly precise` measuringrinstrurnents, have given rise 'w the need for asuiteble means for accurately recording the totalized revolutions of a rotating shaft at a given instant,` particularly Wherethe shaft is mtatinaonteuously at speeds of considerable magnitude. One suehdevelopmerit, which has presentedv ak Substantial problem in this respecarelatesto therapid calibration of` frequency meters ofl the, signalv generator type, eachof whichincludes avariable frequency oscillator. A system has been developed which is adapted tocalibrate such a variable frequency generator by comparison of its generatedA fre; quency with the frequency of a standardzsignal source, and in'whichthe totalizedrevolutions of a continuously rotatingv shaft, at successive instants, represent positional calibrations corresponding Ito different frequenciesof the variable frequency generator. The frequency comparison is effected by. means. of a zero beat detector" which is instrumentaly in generating a control impulse eachtme the frequency of the variable frequency' generator coincides withfa known frequency of the standard ,signal source. The desiredl calibrations areobtained by recording the totallzedrevolutions of theaforementioned shaft each timeafcontrol impulse is. generated by the zero beat detector. Such a systeml is. disclosed andv claimed in' copending application Serial No, 570,714, filed December 30,"l944,' and it will be further referred to hereinafter.

The present invention has for its principal object the provision of a simple and eicient means for accurately recording the totalized-revolutions of a rotatingshaft at a given instant, particularlyin a system of the character above mentioned.

A morespecic object oftheinvention sto provide a novel apparatus. in which provisionis madeffor vtotalizing the revolutionsof a rotating shaft at anyv instant, andin which further provision ismade foi-,temporarilystoring the num-` ber of. the totalized revolutions in a number storage rbankfpancl for automatically recording the storednumber.`

Other objects and features of the invention will be apparent hereinafter.

In ythe accompanying drawings:

Fig, l'is a simple block diagram showing the principal components` or units of a Calibrating system ofthe type above mentioned;

Fig. Zis a furtherschematio illustration of such system;

Fig. 3 isa schematic illustration of a totalizing switch which is employed as apart of the present invention;

Fig. 4 isa side elevational View of the totalizing switch; Y l Fig, 5 is a sectional view taken along line 5-5 of Fig. 4;

Fig. 6 is a sectional View taken along line 6 6 of. Fie- 4;

FigJl isa sectional view vtaken along line l-I of Fig.4; A

Fig. 8 is a detail sectional view taken along line B-B o f-rFig. 6;`

Fig. 9Y is ar. fragmentary sectional view taken longitudinally of the totalizing switch showing more clearly the construction thereof;

Fig. 1() is aV sectional view taken along line lil-lil of Fig.- 9;

Fig. 11 is a sectional'view taken along line H-H of Fig. 9;

Fig. 12isI a perspective view showing the principalfdrivingelementsv by means of which each succeedingl section of the'switch is driven by the preceding section:

Fig. 13 is a diagrammatic illustration showing the number` storage bank associated with the totalizing switch and also the mechanism for operating a recording` apparatus;

Fig. 14 is a perspective View showing one form of thel recordingapparatus and the associated driving mechanism; therefor; and

Fig.. l5 isan illustration, Partly in section and partly in side elevation, of the number storage bank unit and the associated recording apparatus.

As stated above, the present invention is particularly adapted for use in acalibrating system for variable frequency` generators, and it will be described with specic reference thereto, although it is to be understood that the invention is applicable; in any instance where it is desired to accurately record the totalized revolutions oi a rotating shaft.

InvFig. 1; there is showna simple block diagram ofthe principal units of the variable frequency generator calibratingL system above mentioned. 'llliese'units comprise the variable frequency generator I which iste-be calibrated, a standard signal generator 2 capable of producing a band of frequencies over which the variable frequency generator is to be calibrated, a zero beat detector 3 which produces control impulses indicative of frequency coincidence between the units I and 2, and a recording system 4. The present invention resides in a particular arrangement and combination of elements which' constitute the recording system 4; however, in order to clearly describe the invention, a brief description of the calibrating system will first be given.

As mentioned above, the purpose of the calibrating system to which the present invention is particularly applicable is to calibrate, rapidly and accurately, variable frequency generators such as indicated at I in Fig. 1. The variable frequency generator is capable of being tuned over a certain range of frequencies. erator 2 generates signals having frequencies extending over the desired frequency range. For example, this signal generator may generate signals having frequencies extending over the range of 125 k. c. to 250 k. c. and these signals may be spaced apart in frequency by 1 k. c. In operation of the system, the zero beat detector is automatically tuned successively to the frequencies throughout the said range, and at the same time the variable frequency generator I is automatically adjusted throughout its tuning range. Thus, the zero beat detector effectively selects the signals from source 2, one by one. Moreover, it effectively compares the instantaneous frequency of the variable frequency generator I with that of each of the successive signals from source 2. Each time the frequency of the generator I coincides with the frequency selected from source 2, the zero beat detector produces a control impulse which actuates the recording system 4. The sue- The standard signal gen- As previously indicated, the calibrating process is carried out by recording the totalized revolutions of shaft 6 at each instant when the frequency of the variable frequency generator I coin- Acides with a particular frequency of the standard signal source 2. In order to perform the calibrating process very rapidly, the shaft 6 may be rotated at a speed of the order of 1000 revolutions per minute, or higher; and in order to achieve the desired degree of accuracy, it is desired to record the totalized revolutions of the shaft within onetenth of a revolution. This recording operation has presentedY a substantial problem which the cessive recordings constitute the desired calibraf tions.

As shown in Fig. 2, the tuning condensers 5 of the zero beat detector 3 are driven from a shaft 6 through suitable reduction gearing, The shaft 6 is driven by a motor 1. At the same time, the tuning apparatus of the variable frequency generator I is likewise driven from shaft 6 through suitable reduction gearing. At the beginning of each calibrating process, the tuning devices of units I and 3 are set at the extreme end of the frequency range, and during the calibrating process the tuning devices are continously operated throughout the frequency range until the other limit thereof is reached.

The variable frequency generator I has a units dial 8 having evenly spaced markings thereon from 0 to 100 and with which there is associated a stationary vernier dial 9. The variable frequency generator also has a hundreds dial I0 which moves at a slower rate than does dial 8 and which is directly connected to the tuning device (not visible) of the variable frequency generator. As a specific example, the shaft 0 may rotate approximately 5000 times during the calibrating process; the shaft II, driving dial 8, may rotate 50 times; and the dial I0 may make onehalf revolution. This latter dial may be provided with evenly spaced markings from 0 to 50, each of which corresponds to a complete revolution of the dial 8.

As a. specific example, it may be desired to list calibration points every 0.1 k. c. throughout the range of frequencies 125 k. c. to'250 k. c. Recordings may be made every 1 k, c., making a total ofr125 recordings, andthe intermediate points may be obtained by interpolation.

present invention has solved by means of the apparatus now to be described. It will be understood, then, that the present invention is directed specifically to the recording of the totalized revolutions of the shaft 6 and is not concerned with the details of the system briefly described above.

As indicated in Fig. 2, the arrangement or combination of elements provided by this invention comprises a totalizing switch I2 which is driven by shaft 6 through a suitable coupling I3, a num- .fber storage bank I4 electrically associated with and controlled by the totalizing switch, and a suitable recorder I5 associated with the number storage bank and adapted to record the successive numbers which are temporarily stored by the device I4. The specic structure of a preferred form of the apparatus comprising these several elements will now be described.

In Fig. 3, there is illustrated schematically a preferred form of the totalizing switch I2. This switch device comprises a plurality of selector switches, each of which includes ten stationary contacts I6, which are numbered in Fig. 3 from 0 to 9, and a rotating contact arm I'I adapted to successively engage the said contacts. The arms I'I rotate clockwise, as viewed in Fig. 3. As it is desired to record the totalized revolutions of the driving shaft Within one-tenth of a revolution, and since the total number of revolutions during a Calibrating process will extend into the thousands, the totalizing switch preferably comprises five sections as illustrated. The first section I8 is the tenths section, the second section I9 is the units section, the third section 20 is the "tens section, the fourth section 2l is the hundreds section, and the fifthc section 22 is the thousands section. In addition, there is preferably provided a disconnect switch 23, the purpose of which will be explained later. v

The construction and arrangement of this totalizing switch is such that the positions of the movable arms II at any instant are indicative of the totalized revolutions of the driving shaft. Thus, the specific positions of the arms shown in Fig. 3 indicate that the totalized revolutions of the driving shaft is 2494.0. To accomplish the stated end, the rotating arm of the tenths" section I8 is driven by a shaft 24 which is directly tion I9 for each revolution of the rotor arm of section I8. Sections 20, 2| and 22 are each similarly driven from the preceding section by means of gear links 26, 21 and 28, respectively. The gear links are such that each succeeding section is actuated only when the preceding section ansetzen reaches -a certainpcint v'in its v.rotative icycle, as will'berpresentlyseen.

Thestruoture 1 of the totalizing switch .l2 is shown in ".Figs. '4 to 12,'-inclusive- .Referring to Fig, "4, the supporting framework of the switch structure -maycomprise a metal basel 29 on which the various parts arefmounted. A `pair of vertical metal plates V3ll and 3| are mounted on lthe baseas lshown .and have a plurality of 'bolts l32 extending Lbetween them. lFive insulating .plates numberedf33 to'f31 aresupported on the "bolts 32 inspaced relationV by means of spacing collars 38. VEach of theserive insulating plates forms apart of one ofthe ilve zswitch sections above mentioned, and each plate serves to support the stationary contacts IB of the particular switch section. Forwardly ci vthe plate 3| is another insulating plate 39 which is secured directly yto base 29 and is also secured to Vplate 3| through suitable connecting elements 4D. .An extended boss T41 yon plate 3| extends within an opening iniv plate 39 and these two plates rotatably Lsupport the shaft/24 by means of the bearings y43 `and 4-L AThe insulating plate 39 also serves as 'a supporting element for the disconnect switch 23 (Fig. 3) .hereinbefore mentioned. As maybe seen in .1Fig.6, a metal plate 45is secured tothe iront oithe insulating'plate39 and Ais .apertured .at 46 `and `is .also recessed vasat 41. A contact arm 48 is carried iby'shaft '24 and is adapted to engage ,the metalplate 45. lThe .purpose vvof the recess41 is to provide a dead or insulating space 49 to interrupt the `engagement Vbetween .the contact 4arm and the metal plate .-45 lfor `a :purpose to be :described later.

As clearly shown in Fig. 9, ya rod 59 is iiixedly supported by the rear end plate 39 and has its .forwardend seated in va recess :i of shaft 24. A :pin 52 secures the rear end portion of rod 5l) to a-sleeve 53 within which the .said end of rod 59 is disposed. `The sleeve 53 is seated within ap,- ertures of plates V3HE and .33 and is secured to a -disc 54 which, in turn, is secured to plate 39 by means noi Ascrews 55. The rod 50 rotatably supports certain of the rotatable elements of the Vswitch structure as will be presently seen.

The shaft 24, which is coupled to the shaft whose totalized revolutions are to be recorded, lcarries .the contact arm I1 of the tenths section l8of .the switch device. The structure by means ci which `the units" section is .driven from the tenths section is illustrated in Figs. 9 to ll, .this-'structure being typical of the gear links which are provided between the successive sections las above mentioned. At its recessed end, .shaft 24 carries a Amember `51 of the character .shown in Fig. l2. Member 51 has an extending pinV 58 (Fig. 9) which seats 4in a vrecess in an en: larged portion of shaft 24 so that the said member rotates with the shaft. As will .be seen in Fig. 9, the member 51 is .disposed within an `yopening in plate 31. A special pinion 59 (see Fig. 12), having trunnions BU, is rotatably supported beneath A'member 51 and in cooperative relation therewith by means of plates 6l secured to vthe opposite faces of plate 31. Referring specifically to Fig. 12, it will be .noted `that member 51 ccmprises a disc portion 62, having a notch or recess 53 therein, and a pair of uadjacent gear teeth 64.

The notch B3 is aligned with the space between teeth 64, The pinion 59 has alternately disposed short and long teeth65 and B6, the .longteeth `being adjacent thedisc portion 62. The'pinion cooperates -Withmember- 51 in ka manner which will be `presently described.

Afsleeve member 'B1'=(Fig. 29) r:carries vthe :com

tact arm I1 of .the 'next section,'i. e.,-the units .3) vthe two .teeth 64 engage the projecting short tooth .andi an adjacent long tooth .66 of the pinion 59, while the notch 63 engages the same long `tooth to permit :limited rotation of the pinion 59 suicient to move the units arm through onetenth of Jarevolution, 'or in .other words, from onecontactto the next contact. When the long pinion Vtooth leaves the notch B3, the rotation of the .pinion is interrupted and the pinion is again maintained stationary by the disc 62 until .the teeth 64 engage the next .long tooth of pinion 59. Thus, the disc 62 permits rotation of the'pinion by the teeth E4 during one-tenth of each rotative cycle, andthe said disc prevents the pinion from rotating during the remainder of each cycle. The rotation of the pinion operates the gear 68 suiiiciently to rotate the sleeve 61 through onetenth of a revolution. The teeth of gear 68 are similarin all respects to the teeth 64, so that the pinion 59 rotates member 51m unison with member 51.

As stated above, the other sections of the totalizing switch are 'operated by similar struc# tures. However, the element corresponding to member 51 inthe-.succeeding sections is preferably'iormed `asA an integral part of the rotative sleeve. Thus, sleeve 61 has an integral portion 69 `which is similar to member 51 and which functions in the same manner to drive the succeeding switch section during one-tenth of each revolution ofthe sleeve 51. Each of the switch sections, Vother than the tenths section, is moved only Vwhen its .predecessor moves from the 9 contact to the 0 contact. Since all of the switch sections are similar, and the operation of each stems from the tenths section, all movements of the .subsequent sections occur only 'during the interval when Ythe tenths rotor arm is moved between its "9 and il contacts,

As previously mentioned, the stationary contacts of the successive switch sections are carried by the insulating plates 33 to 31, and as shown in Figs. 5 and 7, each of these plates is provided with connection terminals 19 to which the stationary contacts are connected by means of conductors or wires designated generally by reference character 1I. Also, as will be seen in Figs. 4 and 9, each 0f the Contact arms l1 is preferably provided with an associated stop arm 12 which supports the associated contact arm when it is not in engagement with one of the stationary contacts.

Referring now to Fig. 13, the above-described totalizing switch device is included in an electrical circuit with certain other elements, as illustrated. Each of the selector switches comprising the totalizing switch has associated with -it a plurality of triggerable electrical devices which may take the form of gas-filled discharge tubes, such as thyratrons, or cold cathode, three element discharge tubes. Thus, in Fig. 13, thc "tenths'secton i8. of the totalizing switch is shown in detailed association with a number of 'such devices. In the illustration, to conserve space, there are shown only four tubes of the above mentioned Vcharacter numbered 'I3 to 78, respectively, but actually there are ten such tubes associated with'the tenths section of the totalizing switch, one tube for each stationary contact of the selector switch. The selector switch I8 and the associated tubes may be considered as comprising a unit as indicated by the broken line rectangle Tl,

Each of the succeeding sections of the totalizing switch is similarly arranged in association with a plurality of tubes of the same character. Thus, the rectangles-18, 19, 80 and lcorrespond to the uppermost rectangle 11 and each is inf tended to representa succeeding section of the totalizing switch and the associated tubes. In

each instance, for simplicity, a single tube is shown in association with the selector switch.

The tubes employed in association with the totalizing switch constitute the number storage bank |4 (Fig. 2) previously mentioned. These tubes are preferably cold cathode tubes, and each has a cathode 82, a main anode 83, and a starting anode 84. It is characteristic of such a tube that it will not become conductive, even though the normal operating potential is applied to its main anode, until a certain starting potential is applied to its starting anode; and furthermore, once the tube becomes conductive, itV remains so until its cathode-anode circuit is opened. It is also characteristic of such a tube that it emits light during its operation. These characteristics of the particular tube employed may be utilized to accomplish the purposes of the present invention, as will be presently seen. A voltage source 85 supplies the necessary potentials for the various tubes, A circuit-closing device 88 initiates operation of the circuit in response to a control impulse. While the device 86 is shown for purposes of illustration as an electromechanical relay, it may take the form of an electronic device such as a thyratron, particularly if shaft 6 is rotated at such a high speed as to make very rapid action desirable. When the relay 89 is energized, the positive terminal of source 85 is connected to the main anodes of the various tubes through conductor 8l as will be readily apparent. The cathodes of the various tubes are permanently connected through elements 88 and 89 to the negative side of source 85. The various cathode resistors 88 of each group of tubes are connected together and to the coil of a relay as at 89, which in turn is connected to the negative terminal of source 85, The relays associated with the live units 'l1 to 8| are numbered from 89 to 93, respectively. The purpose of these relays will be explained presently.

A starting potential for the various tubes is derived from source 85 through a voltage divider comprising resistors 94 and 95, which are serially connected across the said source through the disconnect switch 23. One end of resistor 94 is connected to the stationary contact plate 45 of the disconnect switch 23 by means` of conductor 9S. Resistor 95 is connected between the rotor arm 49 and ground. In operation, as will presently be seen, the starting potential is applied to the starting anode of a selected tube in each group through the associated selector switches. To this end, the starting anodes of the various tubes are connected respectively to the stationary contacts of the associated selectorv switches'by meansof conductors designated generally by reference character 91. In each instance the circuit for applying the starting potential to the selected tubes is completed through the disconnect switch 23, the shaft 24, and the rotating metallic parts of the selector switch sections. Thus, if the relay 86 were closed at the instant depicted in Fig. 13, the starting potential would be applied to tube 78, and would also be applied to a selected tube of each of the other groups, depending upon the instantaneous positions of the contact arms of the succeeding selector switches. The actuation of the selected tubes (one of each group) eiectively stores the y number represented by the positions of the Variao'us sections of the totalizing switch at the instant of operation. As previously mentioned, the .stored number is recorded by means of apparatus presently to be described.

The reason for providing the disconnect switch 23 may now be seen. It will be recalled that during theone-tenth of a revolution of the driving shaft when the tenths arm passes from 9 to 0, two or more of the switch arms move loetween adjacent contacts, but this does not happen at any other time.` Owing to inevitable mechanical imperfections and backlash, it is conceivable that if relay 86 closed at the instant shaft 6 was at a number, say 4357.95, then the 7" might be stored in the units section, and the next number to appear, namely 0, would be stored in the tenths section, thereby causing the stored number to be 4357.0, whereas the correct number which should have been stored is 4358.0. The purpose of the disconnect switch 23 is to prevent such error. The rotating arm of this switch is directly coupled mechanically to the tenths rotor arm and bears a xed angular relation thereto. The dead space 49 is such that switch 23 opens just before the .tenths" rotor arm leaves contact 9 and the said switch closes Vjust after the said arm reaches contact 0. Since the disconnect switch 23 is serially included in the circuit controlled by the selector switches, the latter are rendered electrically inoperative during the throw-over period, thus eliminating any possibility of error if a control pulse happened to occur during that period.

Relay 86 is momentarily energized by a control impulse received from the zero beat detector previously mentioned, and this relay is provided with lock-in contacts 98 in addition to its main contacts 99. When the relay is momentarily energized, a lock-in circuit is completed which includes an energizing source |09. One of the lockin contacts is carried on a pivoted arm IDI which is connected through a link |82 to a second pivoted arm |03. The purpose of this arrangement will be explained later.

The relays 89 to 93, heretofore mentioned, jointly control an energizing circuit for a solenoid |04 which forms part of the recording mechanism presently to be described. To this end, the contacts of the said relays, bearing the numbers |05 to |09, are serially included in an energizing circuit for the solenoid |84 including the source |00. Therefore, when all of the said relays are energized, the solenoid |94 is energized.

'I'he armature H0 of solenoid |94 is connected through a crank arm to a rotatable shaft I2. At its other end the armature H0 carries a pawl ||3 which engagesa ratchet member H4, yThe functions of the shaft H2 and ratchet member H4 will be described later. The armature H0 also carries a projecting nger ||5 having an ln` f agrees 'clined cam portion IISS'whchisr adapted-to engage a roller ||1 on the ,arm -|03. The entire armature assembly is urged toward the right, as viewed in Fig. 1,3, andis normally maintained in vits right-hand position, by means of a spring I I8.

Referring now to Figs..14 and 15, all of the tubes (13, 14, etc.) are arranged in a bank which is generally designated by reference character lit. In Fig. l14: the tubes are represented as squares. Each horizontal row represents the tubes of one group. The tubesare disposed within an enclosure with whichthere is associated 'a camera |'2I. The pur-pose of this arrangement is to photographically record the totalized revolutions of the shaft (Fig. 2) byfmaking aphotographic record of the tubeswhich are actuated each time a recording operation is instituted by a control impulse received by therelay 86 from the zero beat detector. A lens |22 ,is adapted to 4focus thev light rays from the actuated tubes onto a normally stationary film |23, Within the camera 12|. The nlm is movably supported by suitable pulleys or rollers ,represented generally at |24, and it passes around adriving roller |25 mounted on a shaft 26, which carries the ratchet member ile. A shutter member |21, having a window |23 therein, isecarried by a `rotatable shaft |29. 'The shutter |21 has a-,shoulder |30 which coopverates with a stationary stop |'3'|. The shutter is normally in the position shown with its shoulder against the stopV |.3|, It will be noted that the window |28. is normally out of vline with the lens |22 and the ilm |23. The shaft |29 is connected through suitable gearing |32 to shaft H2.

The operation ofthe complete totalizing and recording system will now be described with particular referenceA to Figs. 13 to 15. Normally, the relay B5 is deenergized and the system is inoperative. At such time, one ofthe frames of the nlm |23 is in a position to receive the light rays from the tubes butthelatter are inoperative and therefore emit substantially no light. Moreover, the shutter |21 is in its normal'position, shown in Fig. 14. Of course it will be realized that the totalizing switch is being continuously driven by the shaft 6, whose totalized revolutions are to be recorded at the desired instants.

When a controllingimp'ulse is received by reley 8S from the zero beat detector, as above described, the relay is momentarily energized and locks itself in through its holding contacts 98. The closure of relay contacts-99 applies an operating potential to the main anodes of all of the tubes (13, 14, etc.) by way of conductor 81, but the tubes remain deionized until a suitable potential is applied to their starting anodes. The voltage divider 947-95 applies 'a `starting potential to one tube'of each group, depending upon the position of the associated selector switch at that instant. By wayof`A example'the voltage source 85 may supply I 85 volts'andthe voltage divider 94--95 may supply-l100 volts to the starting anode of each selected tube.v The selected tube vof each group is thus ionized and commences to conduct current, with the result that its anode-cathode potential isi reduced'to about 'Z0 volts. The resistance( of each of the resistors .Sie is made equal tothe resistance of the assoelated coils of relays 89, 90, etc., and, therefore, approximately 57.5 volts will appear acrossv each relay coil, which biases the cathode and starter anodes of the non-selected tubes positive yby that amount. Further rotation of the totalizing switch will therefore Vapply. about 42.5'volts`between the starter anode and cathode of each subsequently selected tube, but this voltage is insufficient to ionize those tubes. Thus, after relay contacts 99 are closed, the rst tube of each group to be selected becomes ionized while the other tubes remain deionizedv even though the associated selector switch successively closes the circuits to their starting anodes. v'Iheselectedtubes remain ionized until the relay contacts 99 are opened. Thus, the total number of vrevolutionsthrough which the rapidly rotating shaftl has revolved at a given instant isl stored4 in the number storage bank constituted by the various tubes.

The energization ofA thei'lve relays numbered from B9 to 93 by the operation of one tube of each group effects energizatiorl of the solenoid |64 as previously indicated. Consequently, the armature |10 is moved towardthe left, rotating the shaft I2 anamount suiflcient to cause clockwise rotation of shutter |21, as viewed in Fig. 14, until the window |28 is aligned with the lens |22 and lrn |23. Thellight rays from the actuated tubes are thus'permltted to impinge on the nlm |23 which recordsthem as spots, This recording operation takes place before the finger 5 (Fig. 13) engages roller ||1. As the armature I l0 nearsthe left-hand end of its stroke, the cam surface ||6 vengages roller ||1 and deflects arm |03 upward or counter-clockwise about its pivot, thereby actuating4 lever |0| in the same manner. Consequently, the holding circuit of relay 35 is broken and `therelay contacts 99 are opened, thereby causing deionization of the activated'tubes. As va. result,yth e relays 89 to 93 are deenergized, thereby deenergizing the solenoid I 04.

Immediately following the deenergization of the solenoid |04, the springl |.I8 moves the armature ||0 back to its right-hand position, causing suicient clockwise rotation of ratchet member Mto movethe iilm |23 .suillciently to bring the next frame thereofinto alignment with the lens |22. At the. sametime, the shutter |21 is returned to its normal position against the stop I3 but as the tubes .(13 to16, etc.) have already been deenergized by contacts 99, no false record is made.

The apparatus is now initsinoperative condition and awaits` the next control impulse. Each time a control impulseisreceived, the above described operation takes place, but -it lwill be understood that diierent ones of the tubes will be activated according to the positions of the selector switches at each successive instant of operation.

The positions of the recorded spots in each frame of the film ,indicate the totalized revolutions of the shaftvv corresponding to a particular frequency of the frequency meter The nurnbers thus recorded are listed as calibrations of the frequency meter dial. If desired, the nlm may be suitably marked `to. facilitate the reading of the recorded numbers.

Mention has been made previously of the possible use of an electronic device, such as a thyratron, in place of relay k88, In such case, the plate circuit of the Vthyratron could be opened by a switch actuated by rod |02 and lever |03.

In a particular embodiment employing voltages as above mentioned, .the principal elements of the system were as follows:

Tubes 13, 14, etc., were of the type designated 0A4-G.

Each of the resistances constituted'by the coils .of relays 89 to 93 had a value'of 3000 ohms.

Each of the cathode resistors 88 likewise had a value of 3000 ohms.

The resistor 94 had a value of 10,000 ohms.

The resistor 95 had a value of 12,000 ohms.

The series resistor connected to each of the starting anodes of the tubes had a value of 100,000 ohms.

The other resistor connected to each of the starting anode circuits had a value of 1 megohm.

From the foregoing description, it will be seen that the present invention has provided a novel arrangement or combination of elements for recording. rapidly and accurately, the totalized revolutions of a rapidly rotating shaft. By means of such system, it has been found that the recordings can be made to thenearest tenth of a revolution at speeds considerably above 1000 revolutions per minute. It will be understood, of course, that the invention is not limited to the specic apparatus illustrated but is capable of various modifications. For example, recording devices other than that specifically shown might be employed in conjunction with the totalizing switch and the number storage bank.

I claim:

1. In an apparatus for accurately recording the total revolutions of a rotating shaft at a, given instant, a rotary switch device operable by said shaft, said switch device comprising a plurality of selector switches adapted to register the number of revolutions of the shaft, a plurality of normally inoperative gas-filled discharge tubes associated with each of said selector switches, means including said switches for selectively actuating certain ones of said tubes depending upon the positions of said selector switches at the instant of actuation, and means responsive to the operation of the actuated tubes for making a record indicative of the total shaft revolutions at said instant.

2. In an apparatus for accurately recording the total revolutions of a rotating shaft at a given instant, a multi-section switch device operated by said shaft, each section of said switch device comprising a predetermined numberof stationary contacts and a movable contact arm adapted to engage said contacts successively, said switch device further comprising means for establishing a multiple relationship between the movements of the successive sections, a plurality of normally inoperative electrical devices associated with each of said switch sections, said devices being operated by the application thereto of an operating potential and a starting potential, means for applying an operating potential to all of said devices at a given-instant, means controlled by said switch sections for applying a starting potential to certain ones of said electrical devices depending upon the positions of the switch arms at said instant, and means responsive to the operation of the selected devices for making a record indicative of the total shaft revolutions at said instant.

3. In an apparatus for accurately recording at a given instant the total revolutions of a shaft rotating at substantial speed, a first rotary selector switch operable by said shaft and having ten eiective positions so that each position represents one-tenth of a revolution of said shaft, a plurality of succeeding selector switches of the same character, means for operating each succeeding selector switch through one-tenth of a revolution when the preceding switch reaches a certain point in its rotative cycle, whereby the positions of said selector switches at anyinstant are indicative of the total revolutions of said shaft within one-tenth of a revolution, means connected to said switches for retentively registering the positions of said switches at av given instant, thereby to retentively register the number of revolutions of the shaft at that instant, and means for automatically making a record corresponding to the registered number.

4. In an apparatus for accurately recording at a given instant the total revolutions of a shaft rotating at a substantial speed, a first rotary selector switch operable bysaid shaft and having ten effective positions so that each position represents one-tenth of a revolution of said shaft, a plurality of succeeding selector switches of the same character, means for operating each succeeding selector switch through one-tenth of a revolution when the preceding switch reaches a certain point in its rotative cycle, whereby the positions of said selector switches at any instant are indicative of the total revolutions of said shaft within one-tenth of a revolution, a plurality of normally inoperative electrical devices associated with each of said switches for retentively registering the positions of said switches at a given instant, thereby to retentively register the number of revolutions of the shaft at that instant, means responsive to a control impulse for eiiecting selective actuation of said devices according to the positions of said switches, and means responsive to the actuation of the selected devices for making a, record which is indicative of the total revolutions of said shaft at the time of said control impulse.

5. In an apparatus for accurately totalizing the revolutions of a rotating shaft, a plurality of electrically-operable devices the selective energization of which at a given instant is indicative of the total revolutions of the shaft, a rotary selector switch having a rotor arm driven by said shaft and a plurality of stationary contacts engageable by said arm, a plurality of other selector switches each having a rotor arm and stationary contacts, means responsive to movement of said rst rotor arm between a certain pair of the associated contacts for moving one or more of said other rotor arms between adjacent contacts, means connecting said devices respectively to the stationary contacts of said switches, an energizing circuitv connection for said devices extending to the rotor arms of said switches, whereby said connection is extended to certain ones of said devices at a given instant, and a disconnect switch operable by said shaft and adapted to prevent completion of said circuit lconnection during the interval when two or more of the rotor arms are moving.

6. An apparatus for accuratelyrecording at a given instant the total revolutions of a shaft rotating at substantial speed, comprising a rotary switch device operated by said shaft, said switch device including a plurality of selector switches adapted to register the number of revolutions of the shaft, means including a plurality of electrical devices connected to each of said selector switches for retentively registering the positions of said switches at a given instant, thereby to retentively register the number of revolutions of the shaft at that instant, and means responsive to the operation of said last-named means for making a recoi'd corresponding to the registered number.

7'. An apparatus for accurately recording at a given instant the total revolutions Vof a shaft rotating at Substantial. speed, comprising arotary Switch device operated by said shaft, said switch device including a plurality of selector switches adapted to register the number of revolutions of the shaft, means including a plurality of lightemitting gas-iilled discharge tubes connected to each of said selector switches for retentively registering the positions of said switches at a given instant, thereby to retentively register the number of revolutions of the shaft at that instant, said tubes being arranged in a bank in predetermined order, and means responsive to operation of said last-named means for making a photographic record of the actuated tubes, thereby to make a record corresponding to the registered number.

8. An apparatus for accurately recording at a given instant the total revolutions of a shaft rotating at substantial speed, comprising a rotary switch device operated by said shaft, said switch device including a plurality of selector switches adapted to register the number of revolutions of the shaft, a plurality of electric discharge tubes characterized in that each tube requires the application thereto of an operating potential and a starting potential, and once started it operates until the operating potential is removed, means for applying an operating potential to all of said tubes at a given instant, means controlled by said switches for applying a starting potential to certain ones of said tubes depending upon the positions of said switches at said instant, whereby said tubes retentively register the number of revolutions of the shaft at said instant, and means responsive to the operation of the selected tubes for making a record corresponding to the registered number.

DAVID E. SUNSTEIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,446,552 Dunn Feb. 27, 1923 1,982,882 Rhodes Dec. 4, 1934 2,091,768 Noble Aug. 31, 1937 2,098,227 Chauveau Nov. 9, 1937 2,150,240 Nichols Mar. 14, 1939 2,206,827 Prince July 2, 1940 2,313,088 Potts Mar. 9, 1943 2,344,497 Cooney Mar. 21, 1944 FOREIGN PATENTS Number Country Date 519,963 Germany Mar. 6, 1931 

